Lately I met a situation where I needed to create a custom VideoView to my android application. I needed an access to the MediaPlayer object and to add some listeners.
Unfortunately (for me), all members of the VideoView class are private, so even extending the class wouldn’t help me to gain access to its MediaPlayer object (or anything else), I had to make a complete duplicate of the class with my modifications.
Well, although it is sound like I’m complaining for the “hard work”, it is easier than extending the class in this case (since all the source is available…), but it made me really doubt this method of information hiding. Is this a better practice than leaving main components available to modification / access (protected, not public)? I mean, I understand that if I extend the VideoView class, someday maybe they’ll change something in the VideoView class and I might have troubles, but if they’ll change the class, my own (duplicate) version will have a bigger difference from the VideoView class, and my goal is not to create my own video view, but to extend the available VideoView.
When a programmer makes something private, they’re making a bet that nobody else will ever need to use or override it, and so there will be a payoff from the information hiding. Sometimes that bet doesn’t come off. Them’s the breaks.